Continuous casting apparatus with inert gas protector



A ril 22, 1969 R. w. HOLMES CONTINUOUS CASTING APPARATUS WITH INERT GAS PROTECTOR Filed Nov. 19, 1965 MOLTEN METAL INVENTOR RONALD L.W. HOLMES BY W ATTORN Y United States Patent 3,439,735 CONTINUOUS CASTING APPARATUS WITH INERT GAS PROTECTOR Ronald L. W. Holmes, New Providence, N.J., assignor to Union Carbide Corporation, a corporation of New Filed Nov. 19, 1965, Ser. No. 508,708 Int. Cl. B22d 27/00 U.S. Cl. 164-259 2 Claims ABSTRACT OF THE DISCLOSURE This invention relates to continuous casting, and more particularly to means for protecting from atmospheric contamination a stream of molten metal as it flows downwardly from a tundish to a mold.

The invention provides a novel stream protector disposed around such stream between the tundish and mold, which comprises a pair of semi-cylindrical walls, and means mounted adjacent the upper portions of said walls for distributing inert gas uniformly within the protector by discharging such gas downwardly in semi-annular curtains in parallel relation to said stream of metal, and means connecting said walls adjacent mating edges thereof so that the protector and gas distribution means can be opened for inspection of the stream.

A real advantage of the invention is that even when the protector is open, effective protection of the stream is obtained by virtue of such gas distribution means.

In the drawings:

FIGURE 1 is a fragmentary view mainly in elevation of continuous casting apparatus including the invention; and

FIGURE 2 is a perspective view of the protector.

Tundish is provided with two bottom ports or nozzles 12 for discharging two streams 14 of molten metal downwardly into a vertically moving mold 16 when launders 18 are moved laterally out of the path of such streams. A stream protector 20 is attached to each launder 18 to dispense argon on the stream of steel as it leaves the tundish, in a manner which will not disturb the flow. The protector consists of two semi-cylindrical walls hinged at 24 on a vertical axis so that the operator can swing one side away to get a clear, unobstructed view of (or access to) the stream and nozzle. The length of the protector is about seven inches. This gives a small clearance under the tundish of about 78 inch, and about an inch above the top of the mold in its uppermost position. To obtain complete protection a small asbestos cloth skirt 26 is attached to the bottom of the protector to fill the gap to the mold, both at the upper and lower limits of oscillation thereof. The skirt is split to permit the protector to be opened.

3,439,735 Patented Apr. 22, 1969 The protector is mounted on the launder 18 so that when the launder is swung laterally out of line with the nozzle the protector is located around the stream flowing to the mold. A splash plate 30 on the top of the mold is shaped to accommodate the protector in the outboard position.

Each half-wall 25 of the protector is provided with semi-circular inert gas distributing means 32 comprising vertically spaced channels 34 and 36. Such channels are separated by a medial baffle 38 that is spaced at 40 from the adjacent inner surface of wall 25; and a lower baffie 42 that is spaced at 44 from such surface. Inert gas is supplied to both halves of the protector by flexible conduits 46 that are connected to the upper channels 34.

Thus, the inert gas is first distributed in channels 34, then in channels 36, and finally is discharged downwardly as curtains along the inner surface of the protector. This provides a gas shield which prevents atmospheric contamination of the stream of molten steel flowing there through, being effective even when the protector is open for inspection of such stream. In the case of the ferrous metal the inert gas preferably is argon, but any suitable gas may be used that is suitable for protecting the metal stream from atmospheric contamination.

What is claimed is:

1. Apparatus for continuous casting of molten metal comprising, in combination, a tundish having a bottom discharge port for the flow of a stream of molten metal downwardly therethrough, a mold located below said tundish for receiving the so discharged stream of molten metal, and a stream protector disposed around such stream between said tundish and said mold, said protector comprising a pair of semi-cylindrical walls, means for distributing inert gas uniformly within the protector comprising semi-annular channels located adjacent the upper portions of said walls, said channels formed by top, side and end wall portions which provide an opening at the channel bottom for discharging such gas downwardly in semi-annular curtains in parallel relation to said stream of metal and adjacent the inner surfaces of the protector walls, means connecting said walls along the mating edges so that the protector, including said gas distribution means, can be opened for inspection of the stream, and means for supplying inert gas continuously to both of said gas distribution means even when the distributor is open for inspection of the stream.

C 2. Apparatus as defined by claim 1, in which said stream protector includes a flexible skirt attached to the bottom of said protector walls, said skirt being split to provide for the opening of the protector.

References Cited UNITED STATES PATENTS 1,306,761 6/1919 Heminger 249- 3,174,200 3/1965 Keel et al 164-66 FOREIGN PATENTS 1,223,358 2/1960 France.

I. SPENCER OVERHOLSER, Primary Examiner.

ROBERT D. BALDWIN, Assistant Examiner.

U.S. Cl. X.R. 164-281 

